From: Frank Rowand Date: Mon, 19 Sep 2011 14:51:14 -0700 Subject: [PATCH] preempt-rt: Convert arm boot_lock to raw Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/3.12/patches-3.12.0-rt2.tar.xz The arm boot_lock is used by the secondary processor startup code. The locking task is the idle thread, which has idle->sched_class == &idle_sched_class. idle_sched_class->enqueue_task == NULL, so if the idle task blocks on the lock, the attempt to wake it when the lock becomes available will fail: try_to_wake_up() ... activate_task() enqueue_task() p->sched_class->enqueue_task(rq, p, flags) Fix by converting boot_lock to a raw spin lock. Signed-off-by: Frank Rowand Link: http://lkml.kernel.org/r/4E77B952.3010606@am.sony.com Signed-off-by: Thomas Gleixner --- arch/arm/mach-exynos/platsmp.c | 12 ++++++------ arch/arm/mach-msm/platsmp.c | 10 +++++----- arch/arm/mach-omap2/omap-smp.c | 10 +++++----- arch/arm/mach-prima2/platsmp.c | 10 +++++----- arch/arm/mach-spear/platsmp.c | 10 +++++----- arch/arm/mach-ux500/platsmp.c | 10 +++++----- arch/arm/plat-versatile/platsmp.c | 10 +++++----- 7 files changed, 36 insertions(+), 36 deletions(-) --- a/arch/arm/mach-exynos/platsmp.c +++ b/arch/arm/mach-exynos/platsmp.c @@ -73,7 +73,7 @@ static void __iomem *scu_base_addr(void) return (void __iomem *)(S5P_VA_SCU); } -static DEFINE_SPINLOCK(boot_lock); +static DEFINE_RAW_SPINLOCK(boot_lock); static void exynos_secondary_init(unsigned int cpu) { @@ -86,8 +86,8 @@ static void exynos_secondary_init(unsign /* * Synchronise with the boot thread. */ - spin_lock(&boot_lock); - spin_unlock(&boot_lock); + raw_spin_lock(&boot_lock); + raw_spin_unlock(&boot_lock); } static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle) @@ -99,7 +99,7 @@ static int exynos_boot_secondary(unsigne * Set synchronisation state between this boot processor * and the secondary one */ - spin_lock(&boot_lock); + raw_spin_lock(&boot_lock); /* * The secondary processor is waiting to be released from @@ -128,7 +128,7 @@ static int exynos_boot_secondary(unsigne if (timeout == 0) { printk(KERN_ERR "cpu1 power enable failed"); - spin_unlock(&boot_lock); + raw_spin_unlock(&boot_lock); return -ETIMEDOUT; } } @@ -167,7 +167,7 @@ static int exynos_boot_secondary(unsigne * now the secondary core is starting up let it run its * calibrations, then wait for it to finish */ - spin_unlock(&boot_lock); + raw_spin_unlock(&boot_lock); return pen_release != -1 ? -ENOSYS : 0; } --- a/arch/arm/mach-msm/platsmp.c +++ b/arch/arm/mach-msm/platsmp.c @@ -30,7 +30,7 @@ extern void msm_secondary_startup(void); -static DEFINE_SPINLOCK(boot_lock); +static DEFINE_RAW_SPINLOCK(boot_lock); static inline int get_core_count(void) { @@ -50,8 +50,8 @@ static void msm_secondary_init(unsigned /* * Synchronise with the boot thread. */ - spin_lock(&boot_lock); - spin_unlock(&boot_lock); + raw_spin_lock(&boot_lock); + raw_spin_unlock(&boot_lock); } static void prepare_cold_cpu(unsigned int cpu) @@ -88,7 +88,7 @@ static int msm_boot_secondary(unsigned i * set synchronisation state between this boot processor * and the secondary one */ - spin_lock(&boot_lock); + raw_spin_lock(&boot_lock); /* * The secondary processor is waiting to be released from @@ -122,7 +122,7 @@ static int msm_boot_secondary(unsigned i * now the secondary core is starting up let it run its * calibrations, then wait for it to finish */ - spin_unlock(&boot_lock); + raw_spin_unlock(&boot_lock); return pen_release != -1 ? -ENOSYS : 0; } --- a/arch/arm/mach-omap2/omap-smp.c +++ b/arch/arm/mach-omap2/omap-smp.c @@ -44,7 +44,7 @@ u16 pm44xx_errata; /* SCU base address */ static void __iomem *scu_base; -static DEFINE_SPINLOCK(boot_lock); +static DEFINE_RAW_SPINLOCK(boot_lock); void __iomem *omap4_get_scu_base(void) { @@ -68,8 +68,8 @@ static void omap4_secondary_init(unsigne /* * Synchronise with the boot thread. */ - spin_lock(&boot_lock); - spin_unlock(&boot_lock); + raw_spin_lock(&boot_lock); + raw_spin_unlock(&boot_lock); } static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle) @@ -83,7 +83,7 @@ static int omap4_boot_secondary(unsigned * Set synchronisation state between this boot processor * and the secondary one */ - spin_lock(&boot_lock); + raw_spin_lock(&boot_lock); /* * Update the AuxCoreBoot0 with boot state for secondary core. @@ -160,7 +160,7 @@ static int omap4_boot_secondary(unsigned * Now the secondary core is starting up let it run its * calibrations, then wait for it to finish */ - spin_unlock(&boot_lock); + raw_spin_unlock(&boot_lock); return 0; } --- a/arch/arm/mach-prima2/platsmp.c +++ b/arch/arm/mach-prima2/platsmp.c @@ -23,7 +23,7 @@ static void __iomem *scu_base; static void __iomem *rsc_base; -static DEFINE_SPINLOCK(boot_lock); +static DEFINE_RAW_SPINLOCK(boot_lock); static struct map_desc scu_io_desc __initdata = { .length = SZ_4K, @@ -56,8 +56,8 @@ static void sirfsoc_secondary_init(unsig /* * Synchronise with the boot thread. */ - spin_lock(&boot_lock); - spin_unlock(&boot_lock); + raw_spin_lock(&boot_lock); + raw_spin_unlock(&boot_lock); } static struct of_device_id rsc_ids[] = { @@ -95,7 +95,7 @@ static int sirfsoc_boot_secondary(unsign /* make sure write buffer is drained */ mb(); - spin_lock(&boot_lock); + raw_spin_lock(&boot_lock); /* * The secondary processor is waiting to be released from @@ -128,7 +128,7 @@ static int sirfsoc_boot_secondary(unsign * now the secondary core is starting up let it run its * calibrations, then wait for it to finish */ - spin_unlock(&boot_lock); + raw_spin_unlock(&boot_lock); return pen_release != -1 ? -ENOSYS : 0; } --- a/arch/arm/mach-spear/platsmp.c +++ b/arch/arm/mach-spear/platsmp.c @@ -20,7 +20,7 @@ #include #include "generic.h" -static DEFINE_SPINLOCK(boot_lock); +static DEFINE_RAW_SPINLOCK(boot_lock); static void __iomem *scu_base = IOMEM(VA_SCU_BASE); @@ -36,8 +36,8 @@ static void spear13xx_secondary_init(uns /* * Synchronise with the boot thread. */ - spin_lock(&boot_lock); - spin_unlock(&boot_lock); + raw_spin_lock(&boot_lock); + raw_spin_unlock(&boot_lock); } static int spear13xx_boot_secondary(unsigned int cpu, struct task_struct *idle) @@ -48,7 +48,7 @@ static int spear13xx_boot_secondary(unsi * set synchronisation state between this boot processor * and the secondary one */ - spin_lock(&boot_lock); + raw_spin_lock(&boot_lock); /* * The secondary processor is waiting to be released from @@ -75,7 +75,7 @@ static int spear13xx_boot_secondary(unsi * now the secondary core is starting up let it run its * calibrations, then wait for it to finish */ - spin_unlock(&boot_lock); + raw_spin_unlock(&boot_lock); return pen_release != -1 ? -ENOSYS : 0; } --- a/arch/arm/mach-ux500/platsmp.c +++ b/arch/arm/mach-ux500/platsmp.c @@ -52,7 +52,7 @@ static void __iomem *scu_base_addr(void) return NULL; } -static DEFINE_SPINLOCK(boot_lock); +static DEFINE_RAW_SPINLOCK(boot_lock); static void ux500_secondary_init(unsigned int cpu) { @@ -65,8 +65,8 @@ static void ux500_secondary_init(unsigne /* * Synchronise with the boot thread. */ - spin_lock(&boot_lock); - spin_unlock(&boot_lock); + raw_spin_lock(&boot_lock); + raw_spin_unlock(&boot_lock); } static int ux500_boot_secondary(unsigned int cpu, struct task_struct *idle) @@ -77,7 +77,7 @@ static int ux500_boot_secondary(unsigned * set synchronisation state between this boot processor * and the secondary one */ - spin_lock(&boot_lock); + raw_spin_lock(&boot_lock); /* * The secondary processor is waiting to be released from @@ -98,7 +98,7 @@ static int ux500_boot_secondary(unsigned * now the secondary core is starting up let it run its * calibrations, then wait for it to finish */ - spin_unlock(&boot_lock); + raw_spin_unlock(&boot_lock); return pen_release != -1 ? -ENOSYS : 0; } --- a/arch/arm/plat-versatile/platsmp.c +++ b/arch/arm/plat-versatile/platsmp.c @@ -31,7 +31,7 @@ static void write_pen_release(int val) outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1)); } -static DEFINE_SPINLOCK(boot_lock); +static DEFINE_RAW_SPINLOCK(boot_lock); void versatile_secondary_init(unsigned int cpu) { @@ -44,8 +44,8 @@ void versatile_secondary_init(unsigned i /* * Synchronise with the boot thread. */ - spin_lock(&boot_lock); - spin_unlock(&boot_lock); + raw_spin_lock(&boot_lock); + raw_spin_unlock(&boot_lock); } int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle) @@ -56,7 +56,7 @@ int versatile_boot_secondary(unsigned in * Set synchronisation state between this boot processor * and the secondary one */ - spin_lock(&boot_lock); + raw_spin_lock(&boot_lock); /* * This is really belt and braces; we hold unintended secondary @@ -86,7 +86,7 @@ int versatile_boot_secondary(unsigned in * now the secondary core is starting up let it run its * calibrations, then wait for it to finish */ - spin_unlock(&boot_lock); + raw_spin_unlock(&boot_lock); return pen_release != -1 ? -ENOSYS : 0; }